Map viewers for in-vehicle use have become increasingly widespread throughout recent years. For example, for use in connection with a navigation unit, displaying a geographical map as a map view on an optical output device such as a display is a common application.
Typical map views are two-dimensional (2d) or three-dimensional (3d) representations of a road network. In such applications, the road network is typically modelled by a graph consisting of vertices and edges. In the map view, the roads are illustrated as lines, e.g., with a certain thickness and derived from the edges and vertices of the graph.
Sometimes a higher degree of detail is desired. This may be particularly the case in urban areas where the road network comprises complex structures such as multi-lane crossings, tunnels, flyovers, bridges, etc. Moreover, the environment may be characterized by buildings, vegetation and points of interest (POIs) having a high recognition value. To provide easy orientation, it might be desired to display a more detailed graphical representation of such features in the map view.
In the art, solutions referred to as a 3d map view or often as 3d city map view are known. The 3d map views typically consist of a single 3d model of the landscape, i.e., terrain, buildings, POIs, including the road network and respective texturing of the 3d elements. They may allow for a high recognition value of the 3d map view and may therefore facilitate navigation.
Yet, such solutions face certain restrictions. For example, because the 3d map view is obtained from a single 3d model, it may be difficult to individually adapt the 3d map view according to user preferences and/or visualization needs. This may cause problems, in particular, on the borders of the 3d model where a smooth and continuous transition from the 3d model to the 2d map view using the graph representation of the road network is not possible or only possible to a limited degree. Moreover, the memory resources may be particularly high for a given level of detail for conventional 3d models.
Therefore, a need exists to provide techniques allowing for advanced 3d map views. In particular, a need exists to provide techniques which allow for the possibility to adapt and personalize the 3d map view having a high level of detail and, at the same time, reduce memory and calculation resources.